All things work zone and rural ITS

Month: September 2018

Post navigation

In our last post we discussed an interesting discussion on automated vehicles and work zones that took place as part of ATSSA’s Midyear meetings. Another automated vehicle presentation was made during ATSSA’s Sign Committee meeting. Mr. Jamie Retterath of Vergence Automation (https://vergenceautomation.com/ ) began by discussing the relative advantages and disadvantages of different kinds of sensors. He pointed out that no single device works best in all conditions. He suggested a combination of sensors and software is the best way to “see” in all conditions. The car’s software would then choose the sensor image with the most contrast and clarity.

But the most interesting part of his presentation was a way of positioning vehicles anywhere they travel and in any weather conditions. GPS is not accurate enough to guide vehicles by itself. And the geometry of the road changes frequently due to construction, variations in pavement markings, etc.

He called them fiducial signs, meaning points of reference. Even with a foot of snow, these signs would tell vehicles exactly where they were in relation to the road. A series of small signs, perhaps as small as 12” square, would be posted on both sides of the road similar to what’s shown in the photo above.

These signs would be posted in the digital map. Sensors would see the signs and triangulate their position from them. Anytime the road geometry was changed the next vehicles that drove that stretch would recognize the change and would send that data in to change the digital map. It is a simple and relatively inexpensive way to speed the adoption of autonomous vehicles.

We asked about work zones. Mr. Retterath said the first autonomous car to come across a closed lane would see the obstruction and drive around it. Like other changes it encounters, the vehicle would report the closed lane and it would update the digital map in near real time. The same could be done for lane shifts, crossovers, or other geometric changes.

These signs would improve location accuracy and could help speed the adoption of autonomous vehicles, thus saving many lives. Its just a concept at this point, but it represents yet another clever way of moving Towards Zero Deaths.

The American Traffic Safety Services Association (ATSSA) recently concluded their annual Midyear meetings in Williamsburg, Virginia. Their Innovation Council met on August 23rd. But before the meeting began officially, they held a joint round-table discussion with members of the Automotive Safety Council. The ASC represents manufacturers of automotive safety system components including cameras, LIDAR, radar and other sensors.

The ASC led off by presenting a sort of Automotive Sensors 101 class that explained the different technologies, what they do well, and what they don’t do so well. This was a big help to ATSSA members who must design traffic control devices that these sensors will be able to “see” and react to in the very near future.

Cameras used for lane tracking look out about 500 feet on highways with a viewing angle of 40 to as much as 100 degrees. The viewing distance decreases on city streets while the viewing angle increases. As camera technology improves, they plan to hold the lane keeping range to 150m as there is little benefit to extending it. Instead they will widen the field of view to better detect pedestrians, balls rolling into the street, etc.

Cameras currently see black & white (gray scale) and red. White lane markings are much easier for cameras to see than yellow because white has far better contrast.

The ASC maintained (as we do) that digital maps must be updated in real time. Long term work zones are easy enough to include in digital maps. Short term work zones are more of a problem. And chip seals are the worst as they are short term AND include no pavement markings – just chip seal markers.

As we move from level 3 to 4 and 5 automotive system hardware won’t change much. It will probably decrease in price, but that’s all. Rather the system functionality and human-machine language will be the key differentiators. The algorithms used by the vehicle to decide what is important, what is not, and how the vehicle should react will constantly evolve and improve.

The ASC shared their market forecast for growth in the next few years. In 2020 the first level 5 vehicles will be sold. Level 2 (driver assist) vehicles will total about 13 million vehicles. By 2030 more than 90 million vehicles will have at least level 2 automation and level 5 will total nearly 3 million vehicles. But that means less than 5% of all vehicles on the road in 2030 will be level 5.

There are still very different approaches to level 3 automation. At level 3, vehicles will automatically center in their lanes, follow a route and stop when required. But unexpected conditions, such as work zones, causes the vehicle to return control to the driver. Some manufacturers see level 3 as a step toward levels 4 and 5. But others, especially Google, feel level 3 is dangerous and so will not produce cars requiring human control at any time. Level 3 peaks in 2025 at 2 million vehicles then drops as level 4 and 5 vehicles become more popular and available.

The ASC group told us control will be ceded in work zones. But how that will happen is not clear. Still, they agreed with us on the need for sufficient time for the driver to acclimate before having to make important decisions.

Once the ASC concluded their presentation, Scott McCanna of David Evans & Associates made a presentation from our industry perspective and asked several thought-provoking questions about work zones along the way.

When channelizing devices including cones, drums and delineators are used to redefine a lane, will device spacing become important for automated vehicles? Will we need to maintain some minimal spacing to hold CAVs attention? And what happens when one or two cones are knocked down? Will the automated vehicle become disoriented? Or revert to the old lane markings?

It was further suggested than CAV logic should see drums and cones as a higher priority when choosing a direction of travel than existing pavement markings. Drums, cones, etc. should indicate a change…perhaps one that automatically triggers driver control in the case of Level 3 CAVs.

The time went by very quickly and everyone agreed it was a great first step in building better understanding between our two industries. Future meetings are already planned to build on this and plan for our future.